Excursions around Mammoth Lakes



11,053 foot Mammoth Mountain
Ski area in winter and mountain bike park in summer

Besides our wonderful day trip to the Ancient Bristlecone Forest we enjoyed a few other excursions during our short stay in Mammoth Lakes.  This area of the Sierra Nevada is not only rich with alpine scenery but geologic wonders as well.  Evidence of glaciation and both ancient and recent volcanic activity are scattered all over the place.  We visited an earthquake fissure, two volcanic explosion pits which contain small lakes, the dormant volcanic peak of Mammoth Mountain plus a ‘pile’ of lava columns better known as the Devils Postpile National Monument.

 

One of the Inyo Craters, formed by volcanic explosions

 

The Devils Postpile National Monument

The Devils Postpile is a remarkable geological feature of tall, vertical columns formed by a flow of basaltic lava.  As the molten lava cooled and contracted to solid rock, cracks formed at 120-degree angles to absorb the stress.  Cracks merged with other cracks and created the hexagonal columns.

 

Some columns have been twisted and distorted

 

Many of the columns have collapsed creating a sort of ‘pick-up sticks’ pile of hexagonal rocks at the base of the still intact column formation.  Add to that the bending and folding of the columns by earth movements and you have the chaos of the Devils Postpile.

We hiked around the monument marveling at the huge columns.  There is a trail to the top of the "pile" where the surface of the columns have been polished smooth by glaciers.  So the side view is one of tall pillars of rock and the top view looks like hexagonal paving stones.  Amazing...  Nature uses the hexagon shape in many things - bee hives, soap bubbles, salt flats and turtle shells.

 

The top of the 'pile' looks like paving stones
Notice the parallel grooves or glacial striations carved in the rock by moving glaciers 
 

 

From the Devil's Postpile, we took the trail along the San Joaquin River to Rainbow Falls.  The falls is formed by a lava ledge. The San Joaquin River plunges down this ledge 101 feet into a deep gorge.  Rainbow colors form in the mists below the falls.

 

Rainbow Falls

 

Another trip we took was an afternoon drive north on Highway 395 to Mono Lake, an ancient salt lake covering 60 square miles.  David and I had visited Mono Lake back in the 1980’s before it became the nation’s first “National Forest Scenic Area” enabling the US Forest Service to begin protecting this unique resource.  

Mono Lake with tufa formations near shore
Tufa is formed by the mineral deposits of once flowing springs

Mono Lake is an excellent example of how America’s view of the environment and of using land and water has changed for the better.  Since the 1960’s the city of Los Angeles diverted the fresh water streams that flowed into Mono Lake for its own use.  At the time, most likely the thinking was that a salt lake didn’t need fresh water flowing into it and the people of Los Angeles did need fresh water.  (Why Los Angeles thought it had a right to water more than 350 miles away that never flowed toward the city is a whole other matter, but I won’t even go there.) 

Mono Lake is two-and-a half times as salty as seawater and maybe that made it seem too inhospitable to support much life and thus okay to take the fresh water away.  But the water of Mono Lake teems with life!  Brine shrimp and alkali fly larvae attract millions of migrating birds and many California Seagulls use the lake for nesting grounds and to feed their young.  

 

More tufa formations in the lake

 

Over the years as more and more water was diverted from Mono Lake, the water levels dropped and the chemistry of the lake changed threatening the shrimp and fly larvae and the birds that depended on this food source.  What was once a healthy ecosystem was in real danger of disappearance.  Many people and organizations advocated for protective action for Mono Lake.  And to make a long story short, a compromise was reached in 1994 to return the lake’s level to 6392 feet, twenty feet higher than the historic low.  

 

 

It was good to see the water levels up and the lake recovering.  Once again fresh water flows into Mono Lake keeping it and the life around the lake balanced.  Plant life is making a comeback along the streams that flow again into the lake.  But the water is still ten feet short of the mandated lake level due to the droughts of the last ten years.  It is taking longer than expected for water levels to rise.

Believe it or not, we didn't see everything in the Mammoth Lakes area.  But we needed to move on so we could spend several days in the Ansel Adams Wilderness and hike on the Pacific Crest Trail.  Even when you have all the time you want, there still isn’t enough time to see and do everything.  Maybe next time? 

 

David's Stats:
Days Hiked      3
Total Miles Hiked       8.69
Ave. Miles per Day      2.90
Total Elevation Gain       1,225
Ave. Elevation Gain per day   411